/***********************************************************************************[SolverTypes.h]
Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
Copyright (c) 2007-2010, Niklas Sorensson

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
**************************************************************************************************/

#ifndef CUBE_GENERATOR_SolverTypes_h
#define CUBE_GENERATOR_SolverTypes_h

#include <assert.h>
#include <iostream>
#include <stdio.h>

#include "mtl/Alg.hpp"
#include "mtl/Alloc.hpp"
#include "mtl/IntTypes.hpp"
#include "mtl/Map.hpp"
#include "mtl/Vec.hpp"

namespace minisat {
//=================================================================================================
// Variables, literals, lifted booleans, clauses:

// NOTE! Variables are just integers. No abstraction here. They should be chosen
// from 0..N, so that they can be used as array indices.

typedef int Var;
const Var var_Undef = -1;

struct Lit {
  int x;

  // Use this as a constructor:
  Lit mkLit(Var var);
  Lit mkLit(Var var, bool sign);

  bool operator==(Lit p) const { return x == p.x; }
  bool operator!=(Lit p) const { return x != p.x; }
  bool operator<(Lit p) const {
    return x < p.x;
  } // '<' makes p, ~p adjacent in the ordering.
};

inline Lit mkLit(Var var) {
  Lit p;
  p.x = var + var;
  return p;
}
inline Lit mkLit(Var var, bool sign) {
  Lit p;
  p.x = var + var + (int)sign;
  return p;
}

inline Lit operator~(Lit p) {
  Lit q;
  q.x = p.x ^ 1;
  return q;
}
inline Lit operator^(Lit p, bool b) {
  Lit q;
  q.x = p.x ^ (unsigned int)b;
  return q;
}
inline bool sign(Lit p) { return p.x & 1; }
inline int var(Lit p) { return p.x >> 1; }

// Mapping Literals to and from compact integers suitable for array indexing:
inline int toInt(Var v) { return v; }
inline int toInt(Lit p) { return p.x; }
inline Lit toLit(int i) {
  Lit p;
  p.x = i;
  return p;
}
inline int maxLitToIntValue(int nbVar) { return nbVar + nbVar + 1; }

inline Lit readableLitToLit(int l) {
  if (l < 0)
    return mkLit(-l - 1, true);
  return mkLit(l - 1, false);
}

inline Var readableVarToVar(int v) { return v - 1; }

inline int readableVar(Var v) { return v + 1; }
inline int readableLit(Lit l) { return sign(l) ? -(var(l)) : (var(l)); }
inline int litToInt(Lit l) { return sign(l) ? -(var(l)) : (var(l)); }

inline void showListVar(vec<Var> &v) {
  for (int i = 0; i < v.size(); i++)
    printf("%d ", v[i] + 1);
  printf("\n");
}
inline void showListLit(vec<Lit> &v) {
  for (int i = 0; i < v.size(); i++)
    printf("%d ", readableLit(v[i]));
  printf("\n");
}
inline void showListLitNoLn(vec<Lit> &v) {
  for (int i = 0; i < v.size(); i++)
    printf("%d ", readableLit(v[i]));
}
inline void showListInt(vec<unsigned int> &v) {
  for (int i = 0; i < v.size(); i++)
    printf("%d ", v[i]);
  printf("\n");
}
inline void showListInt(vec<int> &v) {
  for (int i = 0; i < v.size(); i++)
    printf("%d ", v[i]);
  printf("\n");
}
inline void showListBool(vec<bool> &v) {
  for (int i = 0; i < v.size(); i++)
    printf("%d ", v[i]);
  printf("\n");
}

/**
   Remark: v is big enaugh to add the new value.  Moreover, the
   literal l doesn't appear in v.

   @param[out] v, the vector where will be add l
   @param[in] l, the added literal
*/
inline void addInSortedVecLit(vec<Lit> &v, Lit l) {
  int i;
  for (i = v.size() - 1; i >= 0 && toInt(v[i]) > toInt(l); i--)
    v[i + 1] = v[i];
  assert(i < 0 || v[i] != l);
  i++;
  v[i] = l;
  v.setSize(v.size() + 1);
} // addInSortedVec

inline void removeLitFromUnsortedListLit(vec<Lit> &v, Lit l) {
  for (int i = 0; i < v.size(); i++)
    if (v[i] == l) {
      v[i] = v.last();
      v.pop();
      return;
    }
  assert(0);
} // removeLitFromUnsortedList

inline void removeLitFromSortedListLit(vec<Lit> &v, Lit l) {
  bool isIn = false;
  for (int i = 0; i < v.size() && !isIn; i++)
    isIn = v[i] == l;
  if (!isIn)
    return;

  int p = -1;
  for (int i = 0; i < v.size() && p == -1; i++)
    if (v[i] == l)
      p = i;
  assert(p != -1);
  for (; p < v.size() - 1; p++)
    v[p] = v[p + 1];
  v.pop();
} // removeLitFromSortedList

// const Lit lit_Undef = mkLit(var_Undef, false);  // }- Useful special
// constants. const Lit lit_Error = mkLit(var_Undef, true );  // }

const Lit lit_Undef = {-2}; // }- Useful special constants.
const Lit lit_Error = {-1}; // }

//=================================================================================================
// Lifted booleans:
//
// NOTE: this implementation is optimized for the case when comparisons between
// values are mostly
//       between one variable and one constant. Some care had to be taken to
//       make sure that gcc does enough constant propagation to produce sensible
//       code, and this appears to be somewhat fragile unfortunately.

class lbool {
  uint8_t value;

public:
  explicit lbool(uint8_t v) : value(v) {}

  lbool() : value(0) {}
  explicit lbool(bool x) : value(!x) {}

  bool operator==(lbool b) const {
    return ((b.value & 2) & (value & 2)) |
           (!(b.value & 2) & (value == b.value));
  }
  bool operator!=(lbool b) const { return !(*this == b); }
  lbool operator^(bool b) const { return lbool((uint8_t)(value ^ (uint8_t)b)); }

  lbool operator&&(lbool b) const {
    uint8_t sel = (this->value << 1) | (b.value << 3);
    uint8_t v = (0xF7F755F4 >> sel) & 3;
    return lbool(v);
  }

  lbool operator||(lbool b) const {
    uint8_t sel = (this->value << 1) | (b.value << 3);
    uint8_t v = (0xFCFCF400 >> sel) & 3;
    return lbool(v);
  }

  friend int toInt(lbool l);
  friend lbool toLbool(int v);
};

const lbool l_True(minisat::lbool((uint8_t)0));
const lbool l_False(minisat::lbool((uint8_t)1));
const lbool l_Undef(minisat::lbool((uint8_t)2));

inline int toInt(lbool l) { return l.value; }
inline lbool toLbool(int v) { return lbool((uint8_t)v); }

//=================================================================================================
// Clause -- a simple class for representing a clause:

class Clause;
typedef RegionAllocator<uint32_t>::Ref CRef;

class Clause {
  struct {
    unsigned mark : 2;
    unsigned markView : 1;
    unsigned learnt : 1;
    unsigned has_extra : 1;
    unsigned reloced : 1;
    unsigned attached : 1;
    unsigned used : 1;
    unsigned size : 24;
    unsigned markIdx : 32;
    int idxReason : 32;
  } header;
  union {
    Lit lit;
    float act;
    uint32_t abs;
    CRef rel;
  } data[0];

  friend class ClauseAllocator;

  // NOTE: This constructor cannot be used directly (doesn't allocate enough
  // memory).
  template <class V> Clause(const V &ps, bool use_extra, bool learnt) {
    header.mark = 0;
    header.used = 0;
    header.attached = 0;
    header.markIdx = 0;
    header.markView = 0;
    header.idxReason = 0;
    header.learnt = learnt;
    header.has_extra = use_extra;
    header.reloced = 0;
    header.size = ps.size();

    for (int i = 0; i < ps.size(); i++)
      data[i].lit = ps[i];

    if (header.has_extra) {
      if (header.learnt)
        data[header.size].act = 0;
      else
        calcAbstraction();
    }
  }

public:
  void calcAbstraction() {
    assert(header.has_extra);
    uint32_t abstraction = 0;
    for (int i = 0; i < size(); i++)
      abstraction |= 1 << (var(data[i].lit) & 31);
    data[header.size].abs = abstraction;
  }

  int size() const { return header.size; }
  void shrink(int i) {
    assert(i <= size());
    if (header.has_extra)
      data[header.size - i] = data[header.size];
    header.size -= i;
  }
  void pop() { shrink(1); }
  bool learnt() const { return header.learnt; }
  void learnt(uint32_t m) { header.learnt = m; }
  bool has_extra() const { return header.has_extra; }
  uint32_t mark() const { return header.mark; }
  void mark(uint32_t m) { header.mark = m; }

  uint32_t used() const { return header.used; }
  void used(uint32_t m) { header.used = m; }

  uint32_t attached() const { return header.attached; }
  void attached(uint32_t m) { header.attached = m; }
  uint32_t markIdx() const { return header.markIdx; }
  void markIdx(uint32_t m) { header.markIdx = m; }
  int idxReason() const { return header.idxReason; }
  void idxReason(int m) { header.idxReason = m; }

  uint32_t markView() const { return header.markView; }
  void markView(uint32_t m) { header.markView = m; }

  const Lit &last() const { return data[header.size - 1].lit; }

  bool reloced() const { return header.reloced; }
  CRef relocation() const { return data[0].rel; }
  void relocate(CRef c) {
    header.reloced = 1;
    data[0].rel = c;
  }

  // NOTE: somewhat unsafe to change the clause in-place! Must manually call
  // 'calcAbstraction' afterwards for
  //       subsumption operations to behave correctly.
  Lit &operator[](int i) { return data[i].lit; }
  Lit operator[](int i) const { return data[i].lit; }
  operator const Lit *(void) const { return (Lit *)data; }

  float &activity() {
    assert(header.has_extra);
    return data[header.size].act;
  }
  uint32_t abstraction() const {
    assert(header.has_extra);
    return data[header.size].abs;
  }

  Lit subsumes(const Clause &other) const;
  void strengthen(Lit p);

  void print() const;

  inline void showClause() {
    for (int i = 0; i < header.size; i++)
      printf("%d ", readableLit(data[i].lit));
    printf("0\n");
  }

  inline void showClause(std::ostream &certif) {
    for (int i = 0; i < header.size; i++)
      certif << readableLit(data[i].lit) << " ";
    certif << "0\n";
  }
};

//=================================================================================================
// ClauseAllocator -- a simple class for allocating memory for clauses:

const CRef CRef_Undef = RegionAllocator<uint32_t>::Ref_Undef;
class ClauseAllocator : public RegionAllocator<uint32_t> {
  static int clauseWord32Size(int size, bool has_extra) {
    return (sizeof(Clause) + (sizeof(Lit) * (size + (int)has_extra))) /
           sizeof(uint32_t);
  }

public:
  bool extra_clause_field;

  ClauseAllocator(uint32_t start_cap)
      : RegionAllocator<uint32_t>(start_cap), extra_clause_field(false) {}
  ClauseAllocator() : extra_clause_field(false) {}

  void moveTo(ClauseAllocator &to) {
    to.extra_clause_field = extra_clause_field;
    RegionAllocator<uint32_t>::moveTo(to);
  }

  template <class Lits> CRef alloc(const Lits &ps, bool learnt = false) {
    assert(sizeof(Lit) == sizeof(uint32_t));
    assert(sizeof(float) == sizeof(uint32_t));
    bool use_extra = learnt | extra_clause_field;

    CRef cid = RegionAllocator<uint32_t>::alloc(
        clauseWord32Size(ps.size(), use_extra));
    new (lea(cid)) Clause(ps, use_extra, learnt);

    return cid;
  }

  // Deref, Load Effective Address (LEA), Inverse of LEA (AEL):
  Clause &operator[](Ref r) {
    return (Clause &)RegionAllocator<uint32_t>::operator[](r);
  }
  const Clause &operator[](Ref r) const {
    return (Clause &)RegionAllocator<uint32_t>::operator[](r);
  }
  Clause *lea(Ref r) { return (Clause *)RegionAllocator<uint32_t>::lea(r); }
  const Clause *lea(Ref r) const {
    return (Clause *)RegionAllocator<uint32_t>::lea(r);
  }
  Ref ael(const Clause *t) {
    return RegionAllocator<uint32_t>::ael((uint32_t *)t);
  }

  void free(CRef cid) {
    Clause &c = operator[](cid);
    RegionAllocator<uint32_t>::free(clauseWord32Size(c.size(), c.has_extra()));
  }

  void reloc(CRef &cr, ClauseAllocator &to) {
    Clause &c = operator[](cr);

    if (c.reloced()) {
      cr = c.relocation();
      return;
    }

    cr = to.alloc(c, c.learnt());
    c.relocate(cr);

    // Copy extra data-fields:
    // (This could be cleaned-up. Generalize Clause-constructor to be applicable
    // here instead?)
    to[cr].mark(c.mark());
    to[cr].used(c.used());
    to[cr].attached(c.attached());
    to[cr].markView(c.markView());
    to[cr].markIdx(c.markIdx());
    to[cr].idxReason(c.idxReason());
    if (to[cr].learnt())
      to[cr].activity() = c.activity();
    else if (to[cr].has_extra())
      to[cr].calcAbstraction();
  }
};

//=================================================================================================
// OccLists -- a class for maintaining occurence lists with lazy deletion:

template <class Idx, class Vec, class Deleted> class OccLists {
  vec<Vec> occs;
  vec<char> dirty;
  vec<Idx> dirties;
  Deleted deleted;

public:
  OccLists(const Deleted &d) : deleted(d) {}

  void init(const Idx &idx) {
    occs.growTo(toInt(idx) + 1);
    dirty.growTo(toInt(idx) + 1, 0);
  }

  // Vec&  operator[](const Idx& idx){ return occs[toInt(idx)]; }
  Vec &operator[](const Idx &idx) { return occs[toInt(idx)]; }
  Vec &lookup(const Idx &idx) {
    if (dirty[toInt(idx)])
      clean(idx);
    return occs[toInt(idx)];
  }

  void cleanAll();
  void clean(const Idx &idx);
  void smudge(const Idx &idx) {
    if (dirty[toInt(idx)] == 0) {
      dirty[toInt(idx)] = 1;
      dirties.push(idx);
    }
  }

  void clear(bool free = true) {
    occs.clear(free);
    dirty.clear(free);
    dirties.clear(free);
  }

  void popOcc() {
    occs.pop();
    dirty.pop();
  }
};

template <class Idx, class Vec, class Deleted>
void OccLists<Idx, Vec, Deleted>::cleanAll() {
  for (int i = 0; i < dirties.size(); i++)
    // Dirties may contain duplicates so check here if a variable is already
    // cleaned:
    if (dirty[toInt(dirties[i])])
      clean(dirties[i]);
  dirties.clear();
}

template <class Idx, class Vec, class Deleted>
void OccLists<Idx, Vec, Deleted>::clean(const Idx &idx) {
  Vec &vec = occs[toInt(idx)];
  int i, j;
  for (i = j = 0; i < vec.size(); i++)
    if (!deleted(vec[i]))
      vec[j++] = vec[i];
  vec.shrink(i - j);
  dirty[toInt(idx)] = 0;
}

//=================================================================================================
// CMap -- a class for mapping clauses to values:

template <class T> class CMap {
  struct CRefHash {
    uint32_t operator()(CRef cr) const { return (uint32_t)cr; }
  };

  typedef Map<CRef, T, CRefHash> HashTable;
  HashTable map;

public:
  // Size-operations:
  void clear() { map.clear(); }
  int size() const { return map.elems(); }

  // Insert/Remove/Test mapping:
  void insert(CRef cr, const T &t) { map.insert(cr, t); }
  void growTo(CRef cr, const T &t) {
    map.insert(cr, t);
  } // NOTE: for compatibility
  void remove(CRef cr) { map.remove(cr); }
  bool has(CRef cr, T &t) { return map.peek(cr, t); }

  // Vector interface (the clause 'c' must already exist):
  const T &operator[](CRef cr) const { return map[cr]; }
  T &operator[](CRef cr) { return map[cr]; }

  // Iteration (not transparent at all at the moment):
  int bucket_count() const { return map.bucket_count(); }
  const vec<typename HashTable::Pair> &bucket(int i) const {
    return map.bucket(i);
  }

  // Move contents to other map:
  void moveTo(CMap &other) { map.moveTo(other.map); }

  // TMP debug:
  void debug() {
    printf(" --- size = %d, bucket_count = %d\n", size(), map.bucket_count());
  }
};

/*_________________________________________________________________________________________________
  |
  |  subsumes : (other : const Clause&)  ->  Lit
  |
  |  Description:
  |       Checks if clause subsumes 'other', and at the same time, if it can be
  used to simplify 'other' |       by subsumption resolution.
  |
  |    Result:
  |       lit_Error  - No subsumption or simplification
  |       lit_Undef  - Clause subsumes 'other'
  |       p          - The literal p can be deleted from 'other'
  |________________________________________________________________________________________________@*/
inline Lit Clause::subsumes(const Clause &other) const {
  // if (other.size() < size() || (extra.abst & ~other.extra.abst) != 0)
  // if (other.size() < size() || (!learnt() && !other.learnt() && (extra.abst &
  // ~other.extra.abst) != 0))
  assert(!header.learnt);
  assert(!other.header.learnt);
  assert(header.has_extra);
  assert(other.header.has_extra);
  if (other.header.size < header.size ||
      (data[header.size].abs & ~other.data[other.header.size].abs) != 0)
    return lit_Error;

  Lit ret = lit_Undef;
  const Lit *c = (const Lit *)(*this);
  const Lit *d = (const Lit *)other;

  for (unsigned i = 0; i < header.size; i++) {
    // search for c[i] or ~c[i]
    for (unsigned j = 0; j < other.header.size; j++)
      if (c[i] == d[j])
        goto ok;
      else if (ret == lit_Undef && c[i] == ~d[j]) {
        ret = c[i];
        goto ok;
      }

    // did not find it
    return lit_Error;
  ok:;
  }

  return ret;
}

inline void Clause::strengthen(Lit p) {
  remove(*this, p);
  calcAbstraction();
}

inline void Clause::print() const {
  const Lit *pLit = (const Lit *)(*this);
  for (const Lit *end = pLit + header.size; pLit != end; pLit++)
    printf("%d ", readableLit(*pLit));
  printf("0");
}

//=================================================================================================
} // namespace minisat
#endif
